Is changing how the game is hosted even an option ? I haven't seen anything related to this on the SC forums. Right now any multiplayer game I joins lags out and I get dropped right away..but the games do at connect at least, they are just unusably laggy.


The cause of the poor performance for Starcraft 2 is that the residence networks, and wireless, are setup so no device can be a server, it will not allow any incoming traffic. If you are able to change the setting from hosting the game on your local computer to host the game on battle.net it may resolve the problem.

Let us know if you have any questions.


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  • No incoming traffic? How do you use the internet? I think he means incoming connections
    – tzenes
    Aug 3, 2010 at 6:25
  • Does SC2 even support lan games? Maybe they're thinking of the original Stearcraft where you could host games on the local network. Aug 4, 2010 at 2:30

4 Answers 4


If you are able to join, it is not due to the restriction of incoming connections.

Three main possibilities:

  1. The latency of your network connection is to high (ok, that is what lag means). This might be due to some filters in the university (i.e. they scan for P2P packages) which would increase the latency, or you are playing on servers very far away from you. (other possibilities are also possible of course)
  2. Your computer is too slow.
  3. The bandwidth provided for each client is not enough to play (ok, this is pretty unlikely)

Yes, that sounds very plausible. It's the same reason you probably can't ssh into your own computer, even from another machine on campus. A novel solution would be to tunnel out of your network and accessing the internet through said connection. The issue is that the firewall should block any connection to your computer that the machine didn't initiate, so if you hide those initiations through something like an active connection to DynDNS it might work, but I'm not sure. I also don't know the specifics on how you would try that.

However, this should not be an issue for people playing over the same network (like a single campus wireless network, not two different wifi spots on campus) or joining a game, just hosting, so if you can't join a game hosted by someone else, on an outside network, IT is probably lying to you.

  • so ya the results are the same no matter if I'm hosting or not, I'm able to connect but then I lag out. So at least some connections are being made. If there's any sort of diagnostics or tests you think I could do on my side of the network to probe this further let me know, I'll get you the results. I looked at a wireshark dump from a game and it seems to me like everything is getting through the network just at throttled speeds.
    – user1731
    Aug 3, 2010 at 3:13
  • 1
    are you on wireless or lan? most places have much better lan speeds. Aug 3, 2010 at 4:39
  • I think speedtest.com or something of the sort willtell you what your max speed is. Aug 3, 2010 at 6:17

My guess is that it is something that your uni IT people have decided to implement. Where I work on-campus we are able to log into and play sc2 (and most steam games) without any problems (i'm not going to say which uni it is either).


My guess is "no". If you can connect to games at all, then it's not incoming traffic. Your packets are getting all the way to Battle.Net and back.

What I think is really the issue is that Blizzard has said that they don't allow too many connections from one IP address, and because all computers on campus are connecting, probably from a single IP address or maybe a handful. Too many people are playing StarCraft, and so you're getting dropped because Blizzard can't handle the load of so many people from the same IP.

  • Why should Blizzard care how many clients from the same IP connect? There is (AFAIK) no additional effort for the server side if multiple clients from same IP connect.
    – StampedeXV
    Aug 3, 2010 at 14:45
  • I think there is, specifically with what ports they're talking to? I don't know why they care, just that they do.
    – McKay
    Aug 3, 2010 at 18:18

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